To obtain a favorable building/constrution material or its fire resisting/ heat insulating coating by making use of wastes.
The wastes such as waste paper, chips, grain grounds, incinerated ashes, sludge, waste tiles, plasters, etc., are crushed or melted, and after they are infiltrated into a solution of liquid ceramics, they are dried to form the building/construction material in a predetermined shape. The wastes such as waste paper, grain grounds, incinerated ashes, sludge, waste tiles, plasters, etc., are crushed or melted, and after they are infiltrated into the solution of liquid ceramics, they are dried to crush them into a powdered substance, and a fire resisting/heat insulating coating method of the building/construction material is constituted by spraying the powdered substance together with the solution of ceramics on the building/construction material.